GlaxoSmithKline has announced publication in the New England Journal of Medicine, of a randomised, double-blind, placebo controlled study investigating the efficacy and safety of Nucala (mepolizumab) vs placebo as an add-on therapy in patients with relapsing and/or refractory Eosinophilic Granulomatosis with Polyangiitis (EGPA). In the 52-week pivotal phase III study, mepolizumab treatment demonstrated efficacy based on both co-primary efficacy endpoints and all secondary endpoints. Treatment with mepolizumab was in addition to standard of care (glucocorticoids with or without immunosuppressants). Patients treated with mepolizumab had a significantly greater accrued time in remission (defined as a prednisolone/prednisone dose of below 4mg/day and a Birmingham Vascular Activity Score = 0) over the 52-week treatment period compared to placebo, with 28% of patients on mepolizumab achieving remission for at least 24 weeks versus 3% on placebo (p<0.001).
In addition, a higher proportion of patients in the mepolizumab group were in remission at both Weeks 36 and 48 compared to the placebo group (32% versus 3%; p<0.001). More patients treated with mepolizumab achieved remission within the first 24 weeks of the study and remained in remission until Week 52 compared to those receiving placebo (19% versus 1%; p=0.007). There was no difference between the two treatment groups in the proportion of patients experiencing on-treatment adverse events (97% versus 94%) and overall the adverse event profile for mepolizumab was similar to that seen in previous studies with no new safety signals observed.
See: "Mepolizumab or Placebo for Eosinophilic Granulomatosis with Polyangiitis." Michael E. Wechsler et al. N Engl J Med 2017; 376:1921-1932 May 18, 2017 DOI: 10.1056/NEJMoa1702079